aheakn



2 Sheets8heet L (No Model.)

T AHEARN.

LIGHTNING ARRESTER.

Patented Jan. 31,1882.

J m A,

(No Model.) 2 Sheets-Sheet 2.

T. AHEARN.

LIGHTNING ARRBSTER.

Patented Jan. 31,1882.

Y Inventor.

UNITED STATES PATENT OFFICE.

THOMAS AHEARN, OF OTTAWA, ONTARIO, CANADA.

LIGHTNING-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 252,859, dated January 31, 1882.

Application filed October 27, 1881.

To all whom it may concern:

Be it known that I, THoMAs AHEARN, of Ottawa, in the Province of Ontario, Canada, have invented certain Improvements in Li ghtning-Arresters, of which the following is a specification.

My invention relates to lightning-arresters for use in telephone and telegraph stations and like places; and it consists in a metallic cylinder or barin electric connection with the earth,

\ insulated throughout its length on one side,

and arranged to receive spring fingers or plates in metallic contact with the various wires entering the building, so that either the metallic face or the insulated face of the cylinder may be brought into contact with all the fingers simultaneously, and the various wires thereby grounded or insulated, as may be desired; in

providing the cylinder with a threaded shaft passing through a correspondingly-threaded bracket, whereby the cylinder may be moved endwise to bring an unused portion of the insulating material beneath the fingers in an electromagnetic detent, which is automatically withdrawn when an excessive charge or current of electricity passes over the wires, thereby permitting a weight or spring to turn the cylinder or bar and ground thelines; in the combination, with such detent, ot' a local battery to give any amount of power required to operate the detent, and in other details hereinafter set forth.

In the accompanyingdrawings,Figure 1 represents a perspective view of my apparatus complete; Fig. 2, a perspective view of the same without the electromagnetic detent, enlarged to show more clearly the construction of the parts; Fig. 3, a view illustrating thearrangement of the automatic mechanism when used without a special local battery.

A represents a suitable stand or frame, (or it may be the wall ofa building,) to which are secured metal brackets B, the outer ends of which are provided with holes or eyes to re- .ceive the shaft a of a cylinder, 0, and are in electric connection with the earth. The cylinder has a portion of its circumferencecovered with paper or otherwise insulated from end to end, as shown.

In rear of the cylinder O are a series of insulated binding-posts, I), each provided with a spring finger or plate, E, which extends from (N0 model.)

the post outward and bears upon the cylinder. The spring-fingers are of uniform length and bear alike upon the cylinder, which is parallel with the line of posts, as shown. Hence it will be seen that when the insulated face of the cylinder is turned up under the fingers the posts D and the wires which they hold will be insulated from the ground; but when the metallic face of said cylinder is brought into contact with the fingers the wires will be grounded, and in this condition will permit the electricity to pass to the earth, thus avoiding all danger of damage or injury from lightning or excessive charges of electricity.

The insulating material may be varied; but in practice I prefer to use thin paper, for the reason that while it affords complete insula tion against the ordinary working current it will not prevent a strong or powerful charge (particularly of atmospheric electricity, which leaves the line more readily than galvanic electricity) from finding its way through it to the cylinder. Henceits use affords protection in case a storm occurs during the absence of the operator and while the lines are not grounded.

As more clearly shown in Fig. 2, the cylinder 0 is somewhat shorter than the space between the brackets B, and has its shaft a threaded at one end and passed through a correspondingly-threaded eye or hole in its bracket, so that by rotating the shalt the cylinder may be moved endwise, and an unused portion of the insulating material thereby brought under the fingers E. For the purpose of thusrotat .ing the shaft it is furnished with a crank or handle, F, which may also be used to turn the cylinder to bring the insulated or the uninsulated portion into contact with the fingers.

In order that the apparatus may be absolutely safe, I preferably employ an automatic detent and a spring or weight in connection with the cylinder C, so that in the event of a storm occurringin the absence of the operator and while the lines are not grounded, or of the o 'ierators being in doubt as to the necessity of grounding the wires, any excessive charge of electricity shall automatically cause the grounding of them. This may be done either with or without a special local battery, though it is preferred to employ such local battery in order to insure the prompt and efiicient operation of the parts. Referring now to Fig. 1, this arrangement of the apparatus will be explained, four main lines being represented, and each being arranged to control or set into action the automatic devices. The several lines are brought into the office in the usual way; but each has introduced into the circuit just before the wires reach the bindingposts D an electro-magnet, G, as shown. The several armatures H of the electro-magnets G are all in the circuit of a local battery, I, and

are so arranged that when attracted by the magnets they shall be brought into contact with the metallic points J, alsointroduced into the circuit.

Between the local battery and the contactpoints J there is introduced an electro-magnet, K, the armature L of which is provided with a hooked end, 6, which engages with a hook, 0, on a weighted arm, M, secured upon the end of shaft to, and arranged to lean forward slightly out of perpendicular when engaged by the hook ordetent 1). Thus arranged, it will be seen that upon the attraction of the armature L the detent or hook I) will disengage the hook c and permit the weight of arm M to carry the same down, thus bringing themetallic face of the cylinder into contact with the fingers E and grounding the lines. The armatures H of the electro-inagnets Gare so adjusted that the ordinary working current shall be insufficient to attract or draw them down, which adjustment may be efi'ected in the manner represented in connection with armature L in Fig. 2, or by adjustable or varying weights applied in rear of their pivots. It will therefore be readily seen that when working with the ordinary current no effect will be produced upon the grounding device,.but that when the lines becomeheavily charged, as before or during a storm, the armatures H will be much more strongly attracted,and will in consequence be drawn down and made to touch the points J, thereby completing the local-battery circuit and causing the armature L to be drawn down and to release the weighted arm M, as above explained. It will also be seen that any one of the several lines will produce this effect. Where the line is of considerable length the local battery may be dispensed with, as a sufficient charge will be received from the atmosphere to insure the operation of the detent. In such case the line-wires are connected directly with the poles of the electro-magnet K, as in Fig. 3,an excesssive charge of electricity serving to withdraw the armature and release the detent without the aid of a second magnet.

It is apparent that the cylinder 0 may be cut away at one side, so as to leave a free space between the fingers audits surface when in one position; that a spring or other equivalent may be employed in lieu of the weighted arm to turn the shaft, and that in other regards the details of the apparatus are susceptible of modification, the invention consist ing broadly of a mechanism which is automatically thrown into action when the lines become heavily charged, and which serves to ground the lines, and also further consisting in a grounding device which serves to throw all the lines simultaneously into or out of connection with'the ground.

I am aware that an electro-magnet and armature have been placed in a telegraphic circuit and the armature adjusted to overcome the attractionof themagnet when actuated by the working current only, but to be attracted by the magnet, and thereby to ground the line, when an excessive charge of electricity is received in the line; but such arrangement has heretofore been applicable only to a single wire or line. By my improvementeach line is made to control all the others, and the grounding of one insures the grounding ot'all. I am likewise aware that insulated lines or wires have had the insulating-covering reduced in thickness and been provided at the point of such reduction with an earthconnected metal clamp, by which latter any excess of electricity passing along the wire mightpass to the earth, the insulation at the point of reduction being only sufficient to prevent escape of the ordinary working current. I do not therefore claim these features per se.

Having thus described my invention, what I claim is- 1. In a lightning-arrester, the combination of a series of electric conducting-lines, a body in electric connection with the earth, an intermediate body adapted to make and break connection between the line or lines and the earthconnected body, and an electro-magnet adapted and arranged to control the intermediate connection, and thereby to automatically ground all the lines of the series upon the overcharging of one of said lines.

2. In a lightning-arrester, the combination of an electric conducting line or lines, a body in electric connection with the earth,an intermediate movahle body adapted to make or break connection between the line or lines and the earth-connected body, and provided with a weight or spring to effect its movement, and a detent controlled by an electro-niagnet and arranged to hold themovable body in position to interrupt connection with the earth until the magnet is caused by an excessive charge of electricity in the line to withdraw the detent and permit the release of the weight or spring.

3. The combination, substantially as described, of one or more electric conductingiines, each having an electro-magnet in its circuit, an earth-connected body, a detent arranged to hold said body normally out ofeleotric connection with the line or lines, an electro-magnet placed in an open local circuit and arranged to withdraw the detent when in action, and one or more circuit-closers arranged to be actuated by the armatures of the line electro-magnets when the lines are overcharged, whereby the local circuit is closed and the detent caused to be withdrawn.

4.. In combination with a grounding-switch,

a series of electric conducting-lines, and an electro-magnet and armature controlling said switch and adapted and arranged to be thrown into action by each or any of said lines when they become overcharged with electricity.

5. The combination, substantially as shown and described, of the cylinder 0, provided with the gravitating-arm M, insulated on a portion of its surface and in electric connection with the earth, fingers E, bearing upon said cylinder and connected with electric conductinglines, electro-magnets G, introduced into said lines, armatures I and contact-points J, arranged in an open local circuit containing an electro-magnet, K, and armature L, arranged to engage the gravitating-arm M until withdrawn by the electro-magnet K, as and for the purpose set forth.

6. In a lightning-arrester, the combination of an earth-connected cylinder insulated throughout its entire length on one side, and a series of fingers connected with the respective lines to be protected and bearing upon said cylinder, snhstantiallyas shown,whereby all the lines may be simultaneously insulated or grounded by partiallyrotatingthe cylinder.

7. In a lightning-arrester, the combination of an earth-connected rotary cylinder provided with a thin insulating layer on one side, and a series of fingers connected with the lines to be protected and arranged to bear upon the cylinder, whereby the lines may be automatically or manually grounded, as set forth.

8. In a lightningarrester, an earth-connected cylinder insulated on one side and provided with a threaded shaft, said shaft passing through a correspondingly-threaded bracket, whereby the rotation of the shaft is caused to move the cylinder endwise under the finger or fingers bearing thereon, and thus to bring an unused portion of the insulated surface under the finger or fingers.

9. In a lightning-arrester, the combination of two or more electric conductors in independent electric circuits and an earth-connected body adapted and arranged to be moved into or out of contact with all of the conductors simultaneously, substantially as shown and described.

THOMAS AHEARN.

Witnesses: I

H. McRAn, A. H. TAYLOR. 

